Removable door structure

ABSTRACT

A door such as an oven door structure in which an enclosure such as the oven has an access opening with a door for closing the opening mounted for rotation about an axis between closed and open positions with the door being easily removable when desired by moving it to a position between open and closed and moving the door by pushing the door downward against a yieldable urging means in a direction to move a pin of each of two pairs of pins into alignment with a side opening in a slot, moving these pins through the opening followed by moving a second pair of pins out of their openings with the result that the door is completely removed from the enclosure. In the preferred construction a pivotally mounted link arm on each side of the door is movable about an axis spaced from the door axis so that the link arms and the door pivot at different rates and with a cavity in each arm that coincides with a pin removal slot only when the door is in its intermediate removable position so that the door can only be removed in the above manner in this intermediate position. An automatic safety catch is provided so that when the door is removed the hinge mechanism is prevented from closing against the enclosure prior to reinstallation of the door on the hinge mechanism.

United States Patent Doner [541 REMOVABLE DOOR STRUCTURE [72] lnventor: John T. Doner, Marion, Ohio [73] Assignee: Whirlpool Corporation v [22] Filed: Nov. 4, 1 970 [21] Appl. No.: 86,730

Primary Examiner-Carroll B. Dority, Jr.

Attorney-James S. Nettleton, Thomas E. Turcotte, Burton H Baker, Gene A. Heth, Franklin C. l-larter, Anthony Niewyk,

- Robert L. Judd and Hofgren, Wegner, Allen, Stellman & Mc-

Cord

[451 July 18, 1972 571 ABSTRACT ble when desired by moving it to a position between open and closed and moving the door by pushing the door downward against a yieldable urging means in a direction to move a pin of each of two pairs of pins into alignment with a side opening in a slot, moving these pins through the opening followed by moving a second pair of pins out of their openings with the' result that the door is completely removed from the enclosure. In the preferred construction a pivotally mounted link arm on each side of the door is movable about an axis spaced from the door axis so that the link arms and the door pivot at different rates and with a cavity in each arm that coincides with a pin removal slot only when the door is in its intermediate removable position so that the door can only be removed in the above manner in this intermediate position. An automatic safety catch is provided so that when the door is removed the hinge mechanism is prevented from closing against the enclosure prior to reinstallation of the door on the hinge mechanism.

1 1 Claims, 11 Drawing Figures PATENTEDJUH8I972 3,577,259

SHEET 1 OF 3 FIG! mvemoif JOHN T. DONER W BY {3 j ATTORNEYS.

PAIENIEUJuH 81972 3.677 259 sum 2 [IF 3 PATENTED JUL18I97Z I 3 77 259 SHEETBUFS REMOVABLE DOOR STRUCTURE One of the features of this invention is to provide an improved door structure that includes a removable door that can only be removed when in one position intermediate between fully open and fully closed with a yieldable means normally retaining the door locked on the enclosure but having cooperating release means that permits moving the door to release position when it is in the intermediate position.

Another feature of the invention is to provide an improved door structure in which the door may be removed by pushing down on the door whereby the door may be removed without difficulty be even a relatively short person.

A further feature of the invention is to provide an improved removable door structure that includes a safety catch means which functions automatically to prevent an inadvertent closing of the hinge mechanism during the period between removal of the door and reinstallation of the door on the hinge mechanism.

Other features and advantages of the invention will be apparent from the following description of one embodiment as illustrated in the accompanying drawings. Of the drawings:

FIG. 1 is a perspective view of a typical cooking oven on which the door structure of this invention may be used.

FIG. 2 is an enlarged fragmentary sectional detail view looking to the left from inside the oven as viewed from the front of FIG. 1 in the vicinity of the left-hand hinge structure and showing the door and associated structure in three positions with position A being fully closed, B being an intermediate broil and removal position and C being fully open.

FIG. 3 is a vertical sectional view similar to a portion of FIG. 2 and showing the door and associated structure in the intermediate or B position illustrating its removal.

FIG. 4 is an enlarged detail view of a portion of the structure of FIG. 3.

FIG. 5 is similar to FIG. 4 but illustrates the positions of certain parts while the door structure is moving from the closed or A' position to the intermediate or B position.

FIG. 6 is a view similar to FIG. 5 but showing the position of certain parts of the door structure when the door is in fully open or C position.

FIG. 7 is a fragmentary perspective view of a portion of the inside of the door structure at the lower left thereof illustrating details of the mounting arrangement.

FIG. 8 is a perspective view of a catch means employed to prevent closing of the hinge mechanism when the door is removed.

F IG. 9 is a side elevational view looking to the left from outside the oven showing a fragmentary portion of the right-hand hinge structure with the door in place and the disposition of the catch means when the hinge mechanism is opened to the intermediate position. Portion of the door structure have been removed to illustrate details.

FIG. 10 is a detail perspective view of certain elements of the structure of FIG. 9 but with the door removed to illustrate .the operation of the catch means.

FIG. 11 is an enlarged fragmentary front elevational view, taken substantially along the line lll1 of FIG. 10 showing details of the mounting arrangement for the catch means.

In the embodiment illustrated in the drawings the enclosure comprises a household cooking stove oven 10 having an access opening 11 thereto together with a door 12 for closing this opening.

On each side of the enclosure adjacent the bottom of the opening 11 are a pair of side hinge members 13 each of which extends inwardly of the front panel 14 of the oven that surrounds the opening 11. Each member 13 is provided with a forwardly and downwardly projecting nose 15 to each of which is hingedly connected a structural member 16 which is parallel to the other member 16 and normally retained within the interior of the door 12. Thus the structural members 16 are permanently mounted on the hinge members 13 about the lower hinges 17 so that the door 12 is movable between fully closed position and fully open position about the axis defined by the opposite lower hinges 17.

On each side of the interior of the door there is provided a pair of vertically spaced, inwardly extending parallel pins 18 and 19 that extend into a pair of spaced recesses 20 (see FIGS. 2 and 7) on opposite sides of the door with each recess opening toward the interior of the oven in substantial alignment with a panel opening 21 (FIG. 2) in front panel 14.

Each of the side structural members 16 is provided with a pair of spaced elongated slots 22 and 23. A first slot 22 of each pair has an end opening through which the corresponding or upper pin 18 is received. The second slot 23 of each pair has a side opening that opens toward the front of the door and a closed end 24 which in the illustrated embodiment is the upper end. Thus when the door is in mounted position on the oven the pairs of pins 18 and 19 on either side of the door are located in their respective slots 22 and 23 of structural members 16 forming part of the hinge mechanism which is mounted on the oven.

The structure also includes yielding means here shown as a helical compression spring 25 installed in the door, with one of the springs 25 being installed in each side of the door although only one of the springs 25 is illustrated. The springs 25 urge the door in a direction to press a pin 19 of the two pairs of pins into the second slot 23 closed end 24 and away from the corresponding side opening in this slot. Thus in the illustrated embodiment the yielding means or spring 25 bears against a fixed bracket 26 on the interior of the door 12 and using this as a base bears against a slidable plunger piece 27 mounted in the door, which itself bears against an elongated end 28 at the top of the structural member 16 with this elongated end 28 defining the front side of the upper slot 22 which is the side adjacent the front of the door 12.

With this structure the door when in its intermediate position as shown at B in FIG. 2 and most clearly in FIG. 3 is thereupon displaceable relative to the side structural members 16 against the urging of the springs 25 by pushing downward on the door so that the two second slot pins 19 of each pair can be aligned with the side opening of the slot 23 and then the door manipulated by pivoting it to move the pin 19 out of the slot as illustrated by the broken lines in FIG. 3 following which the upper pin 18 of the two pairs of pins can be lifted from its slot 22 thereby removing the door.

The intermediate removal position B of the door 12, shown in FIG. 2, may also advantageously serve as the partially open Broil" position of the door to facilitate broiling operations when the oven 10 is provided with an electrical resistance broil element in an upper portion thereof.

In order to prevent removal of the door from the oven except in the intermediate removal position B there are provided a pair of link arms 29 with one arm being on each side of the oven opening. Each link arm 29 is pivotally mounted about a hinge connection 34 with the hinge 34 being spaced from the hinge 17 of the door so that the door and link arms are moved simultaneously but about different axes. Each link arm 29 is provided with an end cavity 31, here shown as a recess, on the upper surface of the front end of each arm 29. These cavities 31 coincide with a first or upper slot 22 only when the door is in its intermediate removal position, as described. When in this intermediate position and with the cavities and slots coir|- ciding as described the door can easily be displaced by moving it downwardly to compress spring 25 and pivoting the base of the door outwardly as indicated in FIG. 3 so as to permit removal of the lower pins 19 from their slots 25 and resulting removal of the entire door as described.

The invention is illustrated in connection with an oven in a free standing range. It will be appreciated that it also may be employed in ovens of the built-in variety. In such ovens the advantages of the present invention are even more striking in that such ovens are generally higher off the floor increasing the door removal problem for a relatively short person. Thus, the ability to remove the door by pushing down on it greatly facilitates removal of the door and is an important advantage of the present invention.

As shown most clearly in FIGS. 4, 5 and 6 each cavity 31 is bounded by a pair of side shoulders 32 and 33 one of which underlies the corresponding pin 18 to block the downward movement of the door at all positions of the door except the intermediate removal position. Thus when the door is in its normally closed position, or adjacent thereto, the shoulder 33 underlies the pin 18 to block this downward movement (see FIG. 5). When the door is between its intermediate removal position and the fully open position as shown in FIG. 6 the shoulder 32 of each pin underlies the corresponding pin 18 to block removal movement.

The end which is the rear end of each link arm 29 is pivoted about an axis defined by the hinge connection 30. As stated earlier, the other or forward end of the link arm 29 is hingedly connected about a hinge 34 which engages the top of the corresponding structural member 16 immediately adjacent and beneath the first or upper slot 22. Located immediately above the hinge members 13 and inwardly of the front panel 14 are a pair of rollers 35 each having a peripheral groove 36. The bottom edge 37 of each link arm 29 rides in this groove 36 so that as the door is moved between open and closed positions the engagement of the bottom edge 37 of each arm 29 rotates the corresponding-roller 35 which may be made of nylon or the like. In order to releasably retain the door in the intermediate position for broiling operations in the oven or preparatory to removal this bottom edge 37 is provided with a stop portion 38 in the form ofa step.

The hinge connection 30 of each link arm 29 is held in the upper end of a connecting arm 39 whose lower end is pivoted to the hinge member 13 about a hinge pivot 40. Each hinge connection 30 is movably held in an elongated grove 41 at the rear end of the link arms 29 in order to permit movement of the link arms 29 relative to their connecting arms 39 when the door is moved between open and closed positions. Each connecting arm 39 is provided with a helical tension spring 42 one end of which is connected to the innermost end 43 of a spring anchor-13a attached to each hinge member 13, and the other end of which is connected to a bracket 44 on the arm 39. Spring anchor 13a is provided with a series of screw fastener holes, not shown, adapted for alignment with adjustment slots 47 in member 13. Each side hinge member 13 is fastened to the spring anchor- 13a by a pair of screws 45 and 46 which enter the screw fastener holes in anchor 13a via the adjustment slots 47 in members 13. Each hinge member 13 is .provided with two spaced groups of three slots 47 in linear alignment, as shown in FIG. 2, to provide for adjustment of the length of the hinge mechanism which is mounted on the oven comprising side hinge members 13, structural members 16 link arms 29, connecting arms 39, spring anchors 13a, and helical tension spring 42. With the illustrated arrangement the hinge mechanism length can be adjusted approximately plus or minus two inches thus facilitating use of the hinge mechanism in ovens having doors of different weights. With the illustrated arrangement the pair of springs 42 urge the door toward closed position at all times and because of the provision of the pin slots or grooves 41 hold the lower edge 37 of each link arm 29 against its roller 35. Thus the combination of the pair of springs 42 and the stop portions 38 on the arms 29 retain the door in intermediate position for broiling or preparatory to removal when the door has been moved to this position.

The present invention includes means for preventing closing of the hinge mechanism when the door is removed comprising a safety catch 50 (FIG. 8) which, on removal of the door, automatically operates to prevent closing of the hinge mechanism until the door is reinstalled on the hinge mechanism. The spring 42 is relatively strong and when the counterweight afforded by door 12 is removed the hinge mechanism including side hinge member 13, structural member 16 and link arm 29 might close against the oven front panel 14 with considerable force were it not for the provision ofsafety catch 50.

The safety catch 50 comprises a somewhat elongated strip of metal having a flat base portion 50a, and an end portion thereof formed at approximately a right angle to the base portion and provided with notches at 41 and 52 to form a hook portion 53 and with notch 52 being adapted to receive an ear 13a on the top front projection of side hinge member 13. The catch member 50 includes a side recess 54 to receive lower pin member 19 to provide support for catch 50 to hold it in an upper position (see FIG. 9) affording clearance for ear 13a when the door 12 is in place on the hinge mechanism. Catch 50 also includes a slot 55 on its lower edge which slidingly cooperates with the door hinge 17 (see FIG. 11). Hinge 17 comprises a hinge pin which passes through the nose 15 of hinge member 13, the lower end of structural member 16, and slot 55 of catch 50. A pair of spring steel retaining rings 60 such as Truarc E rings manufactured by Truarc Retaining Rings Division of Waldes Kohinoor, Inc. one being installed on either side of catch 50, fasten elements 13, 16, and 50 to hinge 17. The structural members 16 are provided with rectangular apertures 56 above slots 23 which are wider than the distance between notches 41 and 52 but slightly narrower than the catch member 50. On installation of the catch member 50in member 16 the hook portion 53 is cocked at an angle (as indicated in broken line in FIG. 9) and the catch member is inserted in the aperture 56 from the rear of structural member 16 (see FIG. 11), and catch member 50 is then rotated such that the hook projections 53a and 53b overlie the sides of the aperture 56 to maintain the safety catch movably mounted on the structural member 16 with the slot 55 being slidingly received on hinge 17 to provide limited movement of catch 50 in aperture 56 along the axis of member 16. When the door is in place, the lower pin 19 is received in both the slot 23 of member 16 and in the door pin recess 54 of the safety catch, holding the catch in an elevated position (see FIG. 9) so that the projecting hook 53 of the safety catch is above the hinge ear 13a and will clear hinge ear 13a on closing of the door. I

On removal of the door 12, the door is pushed down and manipulated as described above to remove it. Such removal of the door thereby removes the door pin 19 which supports the safety catch during normal use of the oven from slot 23. The safety catch 50 is then free to automatically move downward in aperture 56 under the influence of gravity to its lowermost position (illustrated in FIG. 10) guided by the projections 53a and 53b on the hook member and the recess 55 on the lower edge portion of catch 50 which slidingly cooperates with the hinge 17. Thus, on removal of the door, the catch 50 automatically moves downward to its lowermost position under the influence of gravity and in such position the projecting hook portion 53 of the safety catch is in interference relationship (see FIGS. 10 and 11) with the projecting ear 13a of the side hinge member 13 such that the hinge mechanism cannot be closed beyond this point.

On reinstallation of the door, the insertion of the lower pin 19 carried by the door as described above will cause pin 19 to enter recess 54 of the safety catch and if the door is pushed down and manipulated into the installed position, the pin 19 will carry the safety catch 50 to the raised position illustrated in FIG. 9 wherein the safety catch 50 will clear the ear 13a on rotation of the door about its hinge axis defined by hinge 17. Thus, the safety catch 50 provides positive means for automatically preventing an inadvertent closing of the hinge mechanism'during the period between the removal of the door and reinstallation of the door on the hinge mechanism.

In the preferred structure, as illustrated, each of the side hinge members 13 has mounted thereon a spring anchor 13a, a structural member 16, a link arm 29 through the corresponding connecting arm 39 and a spring 42 to provide a hinge mechanism subassembly which can be assembled together and then mounted on the enclosure. This subassembly is installable on and removable from the enclosure as a mechanical unit. Thus in the specific embodiment the above described mechanical unit includes the members 13, 13a, 16, 29, 39 and 42.

Having described my invention as related to the embodiment shown in the accompanying drawings, it is my intention that the invention be not limited by any of the details of description, unless otherwise specified. v

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A door structure, comprising: means forming an enclosure having an access opening; a door for closing said opening movable about an axis between closed and open positions and having a pair of spaced recesses; a pair of side hinge members mounted on said enclosure; a pair of structural members each hingedly connected to a said hinge member; pairs of spaced pins on said door extending into each of said recesses; means on each said structural member providing a pair of spaced elongated slots, a first slot of each pair having an end opening and the second slot of each pair having a side opening and a closed end, the pins of each pair of pins being locatable in each pair of slots when the door is mounted on said structural members; yielding means urging the door in a direction to press a pin of each pair into a said second slot closed end and away from the corresponding side opening, the door when in an intermediate removal position between fully open and fully closed positions being thereby displaceable relative to said structural members against the urging of said yieldable means for aligning a second slot pin of each said pair with a side opening for movement therethrough followed by removal of the first slot pins through said first slot end openings in removing the door from the structural members and thus from said enclosure; a pair of link arms; means pivotally mounting each arm for pivotal movement with said door about an axis spaced from said door axis; and means providing a cavity in each arm coinciding with a first slot of each said pair of slots only when the door is in said intermediate removal position to permit said removing displacing of the door.

2. A door structure, comprising: means forming an enclosure having an access opening; a door for closing said opening movable about an axis between closed and open positions and having a pair of spaced recesses; a pair of said hinge members mounted on said enclosure; a pair of structural members each hingedly connected to a said hinge member; pairs of spaced pins on said door extending into each of said recesses; means on each said structural member providing a pair of spaced elongated slots, a first slot of each pair having an end opening and the second slot of each pair having a side opening and a closed end, the pins of each pair of pins being locatable in each pair of slots when the door is mounted on said structural members; and yielding means urging the door in a direction away from said axis to press a pin of each pair into a said second slot closed end and away from the corresponding side opening, the door when in an intermediate removal position between fully open and fully closed positions being thereby displaceable relative to said structural members by pushing downwardly on the door against the urging of said yieldable means for aligning a second slot pin of each said pair with a side opening for movement therethrough followed by removal of the first slot pins through said first slot end openings in .removing the door from the structural members and thus from said enclosure.

3. The structure of claim 1 wherein each said cavity is bounded by a pair of side shoulders, one of which underlies a first slot pin to block said door displacing at all position of said door except said intermediate removal position.

4. The structure of claim 1 wherein there are provided a holdin of said arms against said stop members.

7. e structure 0 claim 1 wherein each said link arm IS pivotally connected to a structural member adjacent a said first slot.

8. The structure of claim 5 wherein each said hinge member has mounted thereon a said link arm and a said spring means thereby to provide a subassembly comprising a structural member, a hinge member, a link arm and a spring means installable on and removable from said enclosure as a mechanical unit.

9. The structure of claim 7 wherein said link arm is pivotally connected to a connecting arm which is pivotally mounted on said hinge member.

10. The structure of claim 9 wherein each said spring means is connected between a said connecting arm and a said hinge member.

11. A door structure, comprising: means forming an enclosure having an excess opening; a door for closing said opening movable about an axis between closed and open positions and having a pair of spaced recesses; a pair of side hinge members mounted on said enclosure; a pair of structural members each hingedly connected to a said hinge member; pairs of spaced pins on said door extending into each of said recesses; means on each said structural member providing a pair of spaced elongated slots, a first slot of each pair having an end opening and the second slot of each pair having a side opening and a closed end, the pins of each pair of pins being locatable in each pair of slots when the door is mounted on said structural members; yielding means urging the door in a direction to press a pin of each pair into a said second slot closed end and away from the corresponding side opening, the door when in an intermediate removal position between fully open and fully closed positions being thereby displaceable relative to said structural members against the urging of said yieldable means for aligning a second slot pin of each said pair with a side opening for movement therethrough followed by removal of the first slot pins through said first slot end openings in removing the door from the structural members and thus from said enclosure; and catch means for maintaining said side hinge members and said structural members in said intermediate removal position while the door is removed, said structural members having apertures therein to movably receive said catch means for limited movement thereof along the axis of said structural members and each of said catch means being provided with a recess to receive said second slot pin for support of said catch means, said apertures being above said second slots, whereby on removal of the door causing said second slot pin to move away from said hinge mechanism, said catch means under the influence of gravity will automatically move down in front of at least a portion of said side hinge members in interference relation therewith preventing said structural members from moving into fully closed position.

P0405) UNITED STATES PATENT OFFECE (5/69) QERTEECATE or CQY-EQ'NN Patent'No. 677,2 9 Dated .July 18, 1972 Inventor(s) JOHN T. DONER It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as. shown below? Claim 2, line 38, correct the phrase "said hinge members" to read --side hinge members-.

Signed and sealed this 19th day of December 1972.

(SEAL) Attest:

ROBERT GOTTSCHALK Commissioner of Patents EDWARD M.FLETCHER,JR. Attesting Officer 

1. A door structure, comprising: means forming an enclosure having an access opening; a door for closing said opening movable about an axis between closed and open positions and having a pair of spaced recesses; a pair of side hinge members mounted on said enclosure; a pair of structural members each hingedly connected to a said hinge member; pairs of spaced pins on said door extending into each of said recesses; means on each said structural member providing a pair of spaced elongated slots, a first slot of each pair having an end opening and the second slot of each pair having a side opening and a closed end, the pins of each pair of pins being locatable in each pair of slots when the door is mounted on said structural members; yielding means urging the door in a direction to press a pin of each pair into a said second slot closed end and away from the corresPonding side opening, the door when in an intermediate removal position between fully open and fully closed positions being thereby displaceable relative to said structural members against the urging of said yieldable means for aligning a second slot pin of each said pair with a side opening for movement therethrough followed by removal of the first slot pins through said first slot end openings in removing the door from the structural members and thus from said enclosure; a pair of link arms; means pivotally mounting each arm for pivotal movement with said door about an axis spaced from said door axis; and means providing a cavity in each arm coinciding with a first slot of each said pair of slots only when the door is in said intermediate removal position to permit said removing displacing of the door.
 2. A door structure, comprising: means forming an enclosure having an access opening; a door for closing said opening movable about an axis between closed and open positions and having a pair of spaced recesses; a pair of said hinge members mounted on said enclosure; a pair of structural members each hingedly connected to a said hinge member; pairs of spaced pins on said door extending into each of said recesses; means on each said structural member providing a pair of spaced elongated slots, a first slot of each pair having an end opening and the second slot of each pair having a side opening and a closed end, the pins of each pair of pins being locatable in each pair of slots when the door is mounted on said structural members; and yielding means urging the door in a direction away from said axis to press a pin of each pair into a said second slot closed end and away from the corresponding side opening, the door when in an intermediate removal position between fully open and fully closed positions being thereby displaceable relative to said structural members by pushing downwardly on the door against the urging of said yieldable means for aligning a second slot pin of each said pair with a side opening for movement therethrough followed by removal of the first slot pins through said first slot end openings in removing the door from the structural members and thus from said enclosure.
 3. The structure of claim 1 wherein each said cavity is bounded by a pair of side shoulders, one of which underlies a first slot pin to block said door displacing at all position of said door except said intermediate removal position.
 4. The structure of claim 1 wherein there are provided a stop portion on each link arm, and a stop member against which each said stop portion bears when said door is in said intermediate position to retain said door in said intermediate position.
 5. The structure of claim 4 wherein spring means are provided yieldably holding said link arms against said stop members.
 6. The structure of claim 5 wherein said spring means are connected between said link arms and said enclosure for urging said door toward closed position simultaneously with the holding of said arms against said stop members.
 7. The structure of claim 1 wherein each said link arm is pivotally connected to a structural member adjacent a said first slot.
 8. The structure of claim 5 wherein each said hinge member has mounted thereon a said link arm and a said spring means thereby to provide a subassembly comprising a structural member, a hinge member, a link arm and a spring means installable on and removable from said enclosure as a mechanical unit.
 9. The structure of claim 7 wherein said link arm is pivotally connected to a connecting arm which is pivotally mounted on said hinge member.
 10. The structure of claim 9 wherein each said spring means is connected between a said connecting arm and a said hinge member.
 11. A door structure, comprising: means forming an enclosure having an excess opening; a door for closing said opening movable about an axis between closed and open positions and having a pair of spaced recesses; a pair of side hinge members mounted on said enclosure; A pair of structural members each hingedly connected to a said hinge member; pairs of spaced pins on said door extending into each of said recesses; means on each said structural member providing a pair of spaced elongated slots, a first slot of each pair having an end opening and the second slot of each pair having a side opening and a closed end, the pins of each pair of pins being locatable in each pair of slots when the door is mounted on said structural members; yielding means urging the door in a direction to press a pin of each pair into a said second slot closed end and away from the corresponding side opening, the door when in an intermediate removal position between fully open and fully closed positions being thereby displaceable relative to said structural members against the urging of said yieldable means for aligning a second slot pin of each said pair with a side opening for movement therethrough followed by removal of the first slot pins through said first slot end openings in removing the door from the structural members and thus from said enclosure; and catch means for maintaining said side hinge members and said structural members in said intermediate removal position while the door is removed, said structural members having apertures therein to movably receive said catch means for limited movement thereof along the axis of said structural members and each of said catch means being provided with a recess to receive said second slot pin for support of said catch means, said apertures being above said second slots, whereby on removal of the door causing said second slot pin to move away from said hinge mechanism, said catch means under the influence of gravity will automatically move down in front of at least a portion of said side hinge members in interference relation therewith preventing said structural members from moving into fully closed position. 